The Botanical Review最新文献

Leguminosae, the third largest angiosperm family, is a taxon displaying the exceptional diversity of flowers and having great agricultural significance. Despite the broad range of reproductive strategies in this group, floral nectar is a key reward of legumes. The paper aims to summarize the available data on structure, ontogeny, regulation, and possible evolution of the leguminous floral nectaries. To date, detailed characterization of ultrastructure and mode of secretion is available only for a few representatives of the family whereas the majority remains understudied from this perspective. In most cases, regardless of flower symmetry, nectaries are localized between stamens and a carpel. The nectar is usually exuded from modified stomata although the exact mode of secretion by specialized parenchyma may differ between taxa. The leguminous floral nectaries often have certain features of monosymmetry with preferentially abaxial development. Nectaries were independently lost in several lineages, and equally recurrent is the emergence of substitutive, i.e. evolutionary innovative, nectar-producing structures. Floral nectaries possess a certain degree of evolutionary inertia, i.e. they remain stable even in lineages in which flower morphology underwent significant changes compared with an ancestral plan, such as shifts in merism, symmetry, reduction or polymerization of organs and alike. Due to their evolutionary stability, floral nectaries are rarely used in the taxonomy of Leguminosae.

Signalling molecules which as act neurotransmitters in animal such as acetylcholine, dopamine, norepinephrine, epinephrine, serotonin, melatonin, and histamine, have been identified in several plant species. Recent evidence suggests that compound in plants that act as neurotransmitters in animals are typically involved in signalling mechanism and play multifunctional roles in combating biotic stress in plants. Studies examining the roles of neurotransmitters across various biological kingdoms support their crucial functions as signaling and regulatory compounds. It has been suggested that substances may serve as potential mitigator for biotic and abiotic stress by regulating various physiological processes, such as ion homeostasis, hormonal metabolism, and detoxification of oxidative radicals. It is documented that these substances achieve favourable effects through interactions with various phytohormones. The identification of neurotransmitters like compounds (NLC) as biomarkers in plant stress signaling, coupled with their direct role in stress mitigation, highlights their importance in plant physiology and suggests their potential as targets for developing stress-resistant crops. This review analyzes the plant-associated functions of these signalling molecules and compares their roles across diverse horticultural and field crops. The information gathered from a range of species may provide insights into key issues in plant cell signalling, with implications for understanding both growth, metabolism and stress mitigation phenomena. Additionally, this analysis can offer valuable perspectives to guide futuristic research in the field of plant defense and signaling.

Despite its relevance, the study of the inflorescence from a typological point of view generally goes unnoticed in taxonomy, which is fundamental for the comparison of structural elements of the same origin. Pleurothallidinae is not the exception, and its typology has not been studied in detail, causing incorrect interpretations of its structures and misapplication of terms. Here the morphology of Pleurothallidinae inflorescences is analyzed and discussed from a typological point of view, based on the detailed study of structural elements of living material, which are illustrated by photographs and diagrams. The study shows that the subtribe presents a generalized type of inflorescences formed by an abbreviated peduncle and branch system that cannot be seen with the naked eye. Each branch may produce coflorescences of different lengths with one or multiple flowers, also presenting different patterns of succession that determine the general appearance of the plant. Single-flowered coflorescences are dominant in members of the Octomeria and Restrepia affinities, while multi-flowered coflorescences dominate the Acianthera, Lepanthes, Masdevallia, Phloeophila, Pleurothallis and Specklinia affinities. A general and practical classification is established for the different types of coflorescences according to the length and number of flowers produced.

Rootstocks/scions with potential for commercial growing, either for the industry or fresh market, have been one of the main objectives of the fruit breeding programs. Fruit crop breeding has impediments like polyembryony (PE) which is otherwise desirable for clonal plant propagation. In nature PE exist in some fruit crops like citrus, mango, jamun, rose apple, almond etc. In polyembryonic crops, there is an occurrence of the more than one embryo in seed and subsequently numerous seedlings emerge from that single seed. The mother type seedlings are considered nucellar are often vigorous in nature as compared to zygotic ones. In this review, the classification, genetic basis and mechanism of PE has been discussed. In current review, morphogenetic authentication of seedling from polyembronic seed has been discussed in the light of recent research. Transcriptional pathway along with the inheritance pattern and molecular breeding aspects of PE has also been summarized.

Agriculture has undergone a remarkable transformation, transitioning from traditional methods that were used for centuries to technology-driven practices. The advent of image processing and computational intelligence has revolutionized crop production and plant health monitoring. From drones capturing detailed crop growth data to sensors meticulously measuring soil moisture levels, the possibilities are boundless. This review delves into the cutting-edge research advancements in the application of image processing and computational intelligence techniques for botanical fields, with a particular focus on plant health monitoring. First, it provides a comprehensive overview of the diverse imaging sensors employed in agriculture, including visible, near-infrared, thermal, and hyperspectral imaging. Subsequently, it carefully analyzes the advantages and limitations of each sensor type, along with illustrative examples of their utilization in plant health monitoring. The review further explores the application of machine learning and deep learning for automated plant disease identification, highlighting the critical need for standardized datasets, benchmarking protocols, and domain-specific knowledge for effective implementation. In conclusion, the review emphasizes the future challenges and trends in this rapidly evolving field. It serves as a valuable resource, providing insights into the latest trends in computer vision-based plant disease monitoring and identifying gaps that demand further attention from the scientific community.

We provide an overview of the current state of knowledge of island frugivory and seed dispersal and identify knowledge gaps that are important for fundamental research on—and applied conservation of—island ecosystems. We conducted a systematic literature search of frugivory and seed dispersal on islands, omitting large, continental islands. This revealed a total of 448 studies, most (75%) published during the last two decades, especially after 2010. Nearly 65% of them were focused on eight archipelagos. There is a paucity of studies in Pacific archipelagos near Asia and Australia, and in the Indian Ocean. Data on island frugivory and seed dispersal are diverse but highly uneven in geographic and conceptual coverage. Despite their limited biodiversity, islands are essential reservoirs of endemic plants and animals and their interactions. Due to the simplicity of insular ecosystems, we can assess the importance of seed dispersal theory and mechanisms at species and community levels. These include the ecological and biogeographical meaning and prevalence of non-standard mechanisms of seed dispersal on islands; the seed dispersal effectiveness and the relative roles of different frugivore guilds (birds and reptiles being the most important); and patterns of community organization and their drivers as revealed by interaction networks. Island systems are characterized by the extinction of many natives and endemics, and high rates of species introductions. Therefore, understanding how these losses and additions alter seed dispersal processes has been a prevailing goal of island studies and an essential foundation for the effective restoration and conservation of islands.

Fractal dimension (D) can be used to characterise temporal changes of crown architecture of individual trees. Our goal in this study was to analyse seasonal changes in tree crown fractal dimension of two species of deciduous oaks (Quercus castanea and Q. obtusata) coexisting in a natural forest in central Mexico using low cost sampling, and relate these changes to morphological attributes and environmental variables.

Every two months, from May 2017 to September 2018, for each oak species, we photographed fixed portions of the crowns of individual trees, measured their trunk diameters, and obtained average temperature and accumulated precipitation data recorded for the sampling date. From the obtained images, we calculated D values by the semivariogram method using three different variability estimators (square increment, isotropic, and transect variation).

We identified a positive correlation between D and temperature, and a negative correlation between temperature and crown cover.

The fractal dimension (D) of crowns of two deciduous oak species changes according to the tree’s phenological stage. D values varied through time in relation to tree crown phenological variation, but not with crown cover dimension. We propose a model of annual D value fluctuation in deciduous trees, characterised by two high complexity peaks and two low complexity valleys, corresponding to the effects on crown cover of annual periods of leaf abscission and development.

Asteraceae are among the most abundant angiosperm families on oceanic islands. The reproductive biology of Asteraceae is reviewed and the attributes of the family contributing to their success on islands are discussed. Asteraceae are effective dispersers (the small, single-seeded fruits are moved great distances by wind and birds), and colonization is most likely limited by establishment. The pollinators of the colonizing ancestors rarely disperse with them to islands. Divorced from the pollinators of their ancestral habitats, the capitulum of aggregated small, shallow flowers typical of Asteraceae facilitates pollination of colonizers by various novel biotic visitors and by wind. Self-compatible (SC) colonizing ancestors are common, permitting establishment of sexual populations from one or few propagules. However, several large insular lineages of Asteraceae originated from functionally self-incompatible (SI) colonizers that may have also possessed the capacity to set some self-seed. Establishment may also be facilitated by dominance relationships among S-alleles in the sporophytic SI (SSI) system of Asteraceae, increasing cross-compatibility within small populations. Factors potentially promoting outcrossing in SC Asteraceae are: gynomonoecy, with temporal separation of receptive pistillate ray florets and pollen presentation in the hermaphroditic disc florets of a capitulum (interfloral protogyny); and intrafloral protandry where pollen presentation occurs before stigmata become receptive. Dioecy, gynodioecy, and monoecy are infrequent sexual systems in insular Asteraceae. Multiple paternity is similar in island composites to other Asteraceae, suggesting that neither compatible mates nor pollinators are typically limiting. Additional studies, particularly with genomic markers, are needed for more refined insights into mating systems and paternity in island Asteraceae as these results have important conservation implications.